CSC/ECE 517 Fall 2009/wiki1b 1 ch

Advances in Debugging

Introduction

Debugging has been an important part of software development life cycle ever since the first computer program being introduced. Programmers often find the process of finding bugs in their code to be a difficult, slow, tedious, and even frustrating.

During the last decade, debugging techniques and tools have advanced immensely. The most popular tools used by programmers, from beginners to professionals, are probably Eclipse and NetBeans IDE. Both of these tools gained more popularity and success when they became an open-source project, with individuals and companies contributing to the project.

Academic Literature on Debugging

Researchers have been finding ways to increase the productivity of debugging process, from finding an algorithm to creating a tool that implements existing or new debugging techniques. Some of the most popular techniques in debugging are Delta Debugging and Fault Localization.

Delta Debugging

Delta Debugging, developed by Professor Andreas Zeller's group at Saarland University in Germany, is an automatic and systematic technique that deals with isolation of the source of the failure -- often the developer's longest, most demotivating, and most repetitive activity when carried out manually.^[1] The algorithm isolates the difference between the passing and failing test case hence simplifies the number of test cases needed.

Delta Debugging can be applied to isolate the cause of these different applications:

• Failure-inducing input
• Failure-inducing changes (adding / updating / deleting variables, functions, classes, etc.)
• Failure-inducing states (key presses, button presses, mouse clicks, etc.)

Whyline

Whyline is an interactive debugging tool which is designed to help programmers locating the fault by allowing them to ask questions along the source code based on their dependency.

Visual Interactive Debugging Aids (VIDA)

Visual Interactive Debugging Aids (VIDA) is a debugging tool which continuously recommends breakpoints for the programmer based on the analysis of execution information and the gathered feedback from the programmer.

Debugging and The Open-Source Community

There are a lot of open source debugger tools that have become popular among professional developers. They range from stand alone applications to Integrated Development Environment (IDE). They provide many choices for developers to choose whether they want tools for specific languages, operating systems, algorithms, optional plug-ins, etc. Two of the most popular IDEs that are widely used are Eclipse and NetBeans. Both tools are open source, easy to use, and provide cross-platform environment.

Eclipse

IBM developed Eclipse in the late 1990s and turned it over in 2001 to the nonprofit Eclipse Foundation. It became an open-source platform which enabled anyone to build applications using the technology. Eclipse is a popular choice, especially among Java developers, and often compared to NetBeans.

NetBeans

NetBeans is an open-source IDE developed in Java using the NetBeans Platform. NetBeans offer bundles for specific development needs, such as Java EE, Ruby, PHP, and C/C++.

Debugging in Eclipse and NetBeans

Eclipse and NetBeans come with debugging facilities, such as running and stopping the program, setting up breakpoints, keeping track of variables' value, watchpoint, hit count, etc. A nice tutorial for Java debugging with Eclipse can be found here.

Advanced Debugging Tools

Tarantula

Tarantula is a visualization system that displays the results of running suites of tests against software systems. By showing what portions of the code are executed by passed and failed tests, the system helps people identify faults in their programs. (http://pleuma.cc.gatech.edu/aristotle/Tools/tarantula/) Tarantula automates the time-consuming debugging process of stepping through the code and verifying the values at each step. It visualizes the suspicions of statements by different colors, ranging from red, yellow, to green. The statements that are suspicious will be marked with red color, whereas the innocent statements marked by green color.

(Insert example screenshot)

References

[1] Andreas Zeller: Why Programs Fail: A Guide to Systematic Debugging, Morgan Kaufmann, ISBN 1-55860-866-4